Fluorescent strip lighting has long been the stable lighting effect in an aquarium, with the strip lighting often in the form of multiple tubes that are fixed lengthways in the lid of the aquarium.
More recently, intelligent LED-based lights, such as the L1000 BiOrb® Intelligent Light (LED), have allowed sunrise, daylight, sunset and moonlight cycles to be automatically repeated over a 24-hour period. In the BiOrb® system, LEDs are fixed in place in a planar/flat array of a circuit board in the lid of the aquarium, with white and blue light providing directly downwardly incident illumination towards the bottom of the aquarium. The LEDs, as will be understood, provide a high intensity dispersed light source either as a cool narrow bandwidth blue effect or a wider spectral white, with daylight brought about by a microprocessor-controlled increase in the amount and mix of white LED output power relative to blue LED light. In essence, the BiOrb® system regulates illumination through controlling light power intensity from a fixed overhead position.
In some existing aquarium lighting fixtures that provide a “dawn to dusk” mode, the lighting sources simply turn on and off in a sequential mode. For example, the right side of the aquarium is set as the “east” and the left side of the aquarium is set as the “west”. With this type of “dawn to dusk” mode, the lights turn on from right to left and turn off from left to right to mimic the effect of the sun rise and sun set.
An artificial daylight cycle is believed to be beneficial in reducing stress levels in, for example, aquarium fish and moreover provides a better overall visual effect.
With a conventional lighting system where the light source is permanent and is directly downwardly from above the aquarium, the only way that light can be directed to locations other than places which are directly under the light source is by use of a reflector or diffusing lens. The light intensity of the rays deflected from reflector or diffusing lenses are, unfortunately, only a fraction of the full strength than the light intensity from the rays that comes directly from the light source. The amount of light that a creature/organism receives if the creature/organism is under an “overhang” is invariably insufficient to sustain the life of that creature/organism.
However, since light penetration is made a function of power, the current systems (in full day light conditions) can generate excessive light levels towards the top of the aquarium (especially in an attempt to provide requisite light to crevices) and insufficient light levels at the bottom of the tank as a consequence of dispersion and attenuating effects arising from the column of the water. In fact, the limited (time dependent) microprocessor control exercised in the more recent aquarium lighting systems is actually inadequate and really only provides aesthetic consideration for the human viewer, rather than natural environmental conditions for the animals or fish within the aquarium. Moreover, unnecessarily high levels of light can promote unwanted algae growth that, at best, is unsightly and detracts from viewing opportunities. In fact, in the context of a fish tank, too much light or insufficient light can adversely affect aquatic life.
Some specific aquarium lighting fixtures permit the user to adjust the direction of the beam by adjusting the “ball joint” of the fixture that connects to the mounting system of the fixture, but not in the context of LED-based BiOrb® systems.
Relatively sophisticated aquarium lighting systems are provided by companies such as Radion (see http://ecotechmarine.com/products/radion/) and GHL (see http://www.ghl˜store.com/alu-leuchtbalken/led-haengeleuchte-mitras/mitras-1x-6100/mitras-1x-6100_-silber_-hv-_schuko-2-2-2.html). Other LED aquarium systems are provided by Maxspect and described at the website http://www.maxspect.com/.
In any event and in all cases, once set up, the light source is fixed relative to the tank and its contents.
The web article “LightRail 3.5 IntelliDrive 6 rpm Kit” [http://web.archive.org/web/20110806235013/http:www.lightrail3.com/products/3-5lightrail-3-5-intellidrive-6rpm-kit/ from Gualala Robotics Inc., dated August 2011, describes a linear lamp mover assembly for use in growing plants. At the end of travel at the end of the rail, an adjustable time delay allows the linear lamp movement to be paused.
The web article “The Static On Static Lighting: Suggestions for Better Lighting Applications of Photosynthetic Reef Organisms—Moving Light Systems (MLS)” by Anthony Calfo, available in September 2003 [http://www.wetwebmedia.com/staaticlgtg.htm], describes the linear overhead-mounted motorised tracks that permit a light source to move along the course set by the track. A Youtube video “Aquarium plasma lighting on motorised bracket” [http://www.youtube.com/watch?v=IRdO08eL70 uploaded on 30 Nov. 2010] shows an overhead-mounted linear light rail above an aquarium.
Linear moving light systems maintain a constant light angle during linear travel and move the entire light fixture, including the light fixture housing. Generally constant overhead movement of the light source along a linear rail provides insufficient dwell time for sufficient light energy to be received by stationary animals to meet the energy demands of those stationary animals required to sustain health and promote growth. Prior art systems are therefore optically pleasing and serve to provide a visual affect for the human viewer.